1. Field of the Invention
This invention relates to compact domestic ice shavers.
2. Description of the Prior Art
Conventionally, a typical example of this type of ice shaver has been known as disclosed in U.S. Pat. No. 4,565,329 assigned to the assignee of the present application. The prior art example comprises a box-like base frame unit having the top surface beyond which a drive shaft rotated by a built-in motor protrudes, a shaver case unit mounted on the base frame unit and having a shaved ice piece discharge port to which a shaving blade faces, a rotary blade unit fixed to the upper end of the drive shaft within the case unit and having, on its top, a cylindrical hopper, and a cover unit mounted to the shaver case unit to cover an upper portion thereof and having a central openable lid.
In the prior art example, however, the shaving blade is secured to a support seat on the back surface of the shaver case unit by means of screws, thus raising problems that the shaver must be disassembled into individual units each time the shaving blade is exchanged, resulting in a troublesome exchange operation and that it is difficult to maintain parallelism between the surface of the shaver case unit and a cutting edge of the shaving blade and to adjust the amount of protrusion of the cutting edge.
Further, in the aforementioned U.S. patent, danger can be prevented by allowing the rotary blade unit to be rotated only when an auxiliary switch inserted in a motor drive circuit is turned on simultaneously with closure of the openable lid provided for the cover unit and a main switch in the motor drive circuit is then turned on manually.
However, the main switch can be on/off operated externally and this arises another problem that the main switch can not fulfil its danger preventive role if, without turning off the main switch even in the event that the rotary blade unit is not reguired to be rotated, the openable lid is inadvertently closed by erroneously recognizing that the main switch had been turned off and the rotary blade unit is consequently rotated.
Further, the prior art example of the aforementioned U.S. patent is disadvantageous in that when each unit is internally contaminated in use and the shaver is desired to be disassembled for removal of contaminants, special tools for disassembling and reassembling are needed because of structural complexity of the shaver.